This product saved my son's summer by letting him swim as much as he wanted. It never leaked, despite being put to the test by an active 12 year old boy. I'd recommend waiting until you are completely ready to swim before putting the cast cover on because the pressure is uncomfortable. However once my son was in the pool he would have so much fun he forgot about the pressure. He swam, jumped, played, and even dived until I noticed and stopped him from diving. This is a great product!!